In general, lingerie (which is different than underwear) can really backfire if you don't have the body for it. Most men just don't have the combination of abs and *** to pull off a thong.<br />
Women, however usually have enough *** to pull off boyshorts.<br />
(And whether we do or we don't you just want to pull off our boy shorts anyway to get to what's beneath, so you'll always say we look great in them.)
The same reason we still look sexy wearing nothing but a football jersey, and guys still look weird wearing nothing but a bra....
not all girls think that, i looove wearing sexy undies... especially in clothes where you can see them :D